This invention relates to stringed musical instruments in general and, more particularly, to electric guitars and basses having a movable electromagnetic pickup.
The initial design of electric stringed instruments, such as electric guitars and basses, included an electromagnetic pickup device, to detect the mechanical waves of the strings within the magnetic field; and, in turn, the magnetic disturbance is converted to an electric signal, transmitted to a sound amplifying means. The single pickup was positioned under the strings, at a fixed position. In order to improve the musical performance and flexibility of stringed instruments, multiple pickup and movable pickup devices were soon introduced.
The purpose of positioning the pickup along different sections of the vibrating strings is to affect a change in the sound quality of the instrument. The closer a pickup is to the bridge of a stringed instrument, the more it will pick up treble frequencies. As it is positioned closer to the neck part of the instrument, it will increasingly favor bass response. Furthermore, there are, along the vibrating strings, harmonic nodes, locations where the harmonic content of the plucked note is emphasized. These are called sweet spots. Depending on scale length, tuning and the actual note played these sweet spots vary. A movable pickup or multiple pickups can be placed in a location to attempt to capture the desired tonal characteristic.
A stringed instrument with multiple fixed pickups attempts to capture these varying characteristics but is limited by the fixed location of the pickups. To achieve intermediate sounds, output from two pickups must be electronically mixed, resulting in phase shifts; since the two pickups simultaneously record a slightly different waveform of the vibrating string. The musician loses flexibility and precision when using a multiple pickup instrument. This disadvantage has led to development of movable pickup mounting designs.
The first type of movable pickup commonly used is the sliding pickup. The sliding pickup devices are again positioned under the strings. However, the pickup is mounted on a linear translating mechanism, such as a rail. The pickup can be moved longitudinally along a straight path, generally parallel to the path of the strings. The sliding pickup designs have the advantage of more effectively shaping the tonal characteristics of the instrument by allowing placement of the pickup at multiple discrete locations along the string path.
There are, however several drawbacks to the sliding pickup design. Many of these sliding pickups were designed to be positioned before play, and not during play. Alternatively, the position, directly beneath the strings, made it difficult to reposition the pickup during play. If the musician wishes to change the tonal characteristic of the instrument throughout a piece of music, repositioning the sliding pickups may result in an interference of the performance. Another disadvantage of the sliding pickup is the possibility of the pickup mechanism jamming during a transition. If the sliding pickup were to become askew in relation with the rail mechanism, jamming or chattering may result.
A rotating pickup design places the pickup at different angles relative to the string path, which results in shifts in tone, as shown in Pagelli U.S. Pat. No. 5,012,716. Although the rotating disc revealed in '716 can be manually adjusted during play, the maximum angular displacement, wherein the pickups are in continuous electromagnetic communication with the strings, is limited. When exploring a pickup angle in relation to the strings, the musician must keep in mind that the pickups must remain in close proximity directly below the strings. To achieve full communication with all strings, the rotation angle must be limited. The multiple pickups of '716 additionally have the drawbacks discussed previously.
The multiple pickup, sliding pickup, and rotating pickup designs mentioned above, do affect the tonal characteristics of the instrument; however, they all have mechanical and artistic limitations due to their design. Most sliding designs are cumbersome in use and prone to mechanical failure in the field while rotating designs are severely limited in the range of tonal manipulation they offer.
What is needed is a moveable electromagnetic pickup to capture desired tonal characteristics. What is additionally needed is a moveable electromagnetic pickup that is easily moved during play. Further, what is needed is a moveable electromagnetic pickup that will not jam or chatter as it is being moved. What is additionally needed is a moveable electromagnetic pickup that is simple in design and easily manufacturable.